Coaxial switch



Nov. -13, 1962 s. LAPlDUS 3,064,105

COAXIAL SWITCH Filed Nov. 4; 1960 4 Sheets-Sheet 1 F/GJ g1; INV EN TOR.501 ONO/V [A P/Dl/S BY M M A rro /yns s. LAPIDUS 3,064,105

COAXIAL SWITCH 4 Sheets-Sheet 2 50L OMOA/ 1 Nov. 13,1962

Filed Nov. 4, 1960 IN VEN TOR.

Af TOR/Vt" Y5 Nov. 13, 1962 s. LAPIDUS 3,064,105

COAXIAL SWITCH Filed Nov. 4, 1960 4 Sheets-Sheet 5 INVENTOR. ,//4 9sozo/vo/v LAP/00.5

M ATTORNEYS Nov. 13, 1962 s. LAPIDUS COAXIAL SWITCH 4 Sheets-Sheet 4Filed Nov. 4, 1960 7w .m m NL E FVN mm m n 6 H ATTOAM/SYS United StatesPatent 3,064,105 COAXIAL SWITCH Solomon Lapidus, Flushing, N.Y.,assignor to Bogart Manufacturing Corporation, Brooklyn, N.Y., acorporation of New York Filed Nov. 4, 1960, Ser. No. 67,200 28 Claims.(Cl. 200-153) This invention relates to electrical switches for highfrequency power, and more particularly to a three-port coaxial switch.

The general object of the invention is to improve coaxial switches,especially switches for handling a large amount of high frequency powercarried on coaxial line of large dimension.

A more particular object is to provide improved control mechanism foroperating such a switch. A still more particular object is to provide amanually operable handle which turns a half revolution, and which is somounted that it points toward that branch of the switch which has beenconnected to the common port.

Still another general object is to provide a switch which handles highpower efficiently over a relatively wide frequency range, with a smallVSWR (voltage standing wave ratio), and which provides a very highdegree of isolation.

To accomplish the foregoing objects, and other objects which willhereinafter appear, my invention resides in the couial switch elementsand their relation one to another, as are hereinafter more particularlydescribed in the following specification. The specification isaccompanied by drawings in which:

FIG. 1 is a plan view of a switch embodying features of my invention,with the cover plate and handle removed;

FIG. 2a is a view showing the movable member in a dead center position;

' FIG. 2 is a partly sectioned front eievation looking toward the commonand branch ports;

FIG. 3 is a plan view of the mechanism of the switch, with the handleand a top bearing plate removed;

FIG. 4 is a section taken approximately in the plane of the line 4-4 ofFIG. 3;

FIG. 5 is a longitudinal section through one of the stationary ports;

FIG. 6 is a front elevation of the movable U-shaped movable coaxialswitch member, for brevity called a U bend;

FIG. 7 is a section therethrough taken approximately in the plane of theline 77 of FIG. 6;

FIG. 8 is a transverse section taken approximately in the plane of theline 8-8 of FIG. 6;

FIG. 9 is a fragmentary section drawn to enlarged scale and taken in theplane of the line 99 of FIG. 6;

FIG. 10 is a fragmentary section drawn to enlarged scale and explanatoryof the operation of a spring contact ring used for the outer conductor;

FIG. 11 is a fragmentary section explanatory of a support element forthe U bend;

FIG. 12 is a fragmentary view showing a part of the operating handle;

FIG. 13 shows the detent plate of the handle, and is taken on the line13-13 of FIG. 12;

FIG. 14 is a fragmentary section at the outer end of one of theover-the-center pull springs; and

FIGS. 15, 16 and 17 are schematic views explanatory of the operation ofthe switch.

Referring to the drawing, and more particularly to FiGS. l and 2, theswitch comprises a housing 12 having a common coaxial port 14, a branchcoaxial port 16 on one side of the common port, and another branchcoaxial port 13 on the other side of the common port.

3,064,105 Patented Nov. 13, 1952 These branch ports 16 and 18 areequally spaced from the common port 14. In the present case the portshave flange connections for use with standard 3% inch coaxial line, andthe particular connections shown are male connections, but it will beunderstood that one or more of the connections may, if desired, bechanged to be a female connection, in which case the resilient maleprojection 26 for the center conductor is replaced by a hollow orcup-shaped seat, and a flanged outer-conductor exten sion is added tothe flange 22 to provide a similar flange located outwardly or beyondthe female seat, the said parts then being adapted to receive a standardmale connection like that here shown.

Referring to FIG. 2, the enclosed switch housing is provided with amanually operable handle 24. In FIG. 1 the handle 24 and the cover plate26 (FIG. 2) have been removed to expose some of the mechanism. In FIG. 1attention is directed to a U bend coaxial member 30, which, in theposition shown, serves to connect port 14 to port 18, but which may bebodily moved to a position in which it connects port 14 to port 16.

Referring now to FIGS. 15, 16 and 17 of the drawing, the movable member30 is carried by a parallelogram linkage schematically indicated bylinks 32 and 34. The link 32 is pivoted in a fixed bearing at 36, andthe link 34 is pivoted in a fixed bearing 38. At their opposite endsthey are pivoted on the movable U bend 30, so that the links act ascranks. The location of the parts is indicated by broken line brackets.By turning the cranks degrees the U bend 30 is moved away from the ports14 and 18, as shown by the change from FIG. 15 to FIG. 16, and bycontinuing the rotation of the cranks for another 90 degrees the U bendis moved to a position connecting the ports 14 and 16, as shown in FIG.17, instead of connecting the ports 14 and 18, as shown in FIG. 15.

In the particular arrangement here shown the shafts 36 and 38 areparallel shafts extending transversely of and between the coaxialconductors on either side of the common port 14. There are two cranks 32on shaft 36, straddling the U bend 3t), and two additional cranks 34 onshaft 38 also straddling the U bend. The free ends of all four shaftsare pivotally connected to the U bend, and thus by rotation of theshafts the U bend is bodily moved between positions connecting thecommon port 14 with either branch port 16 or 13.

In the present case the shafts 36 and 38 carry gears 49 and 42 of equaldiameter. An intermediate gear 44 meshes with both gears 40 and 42, andinsures equal rotation of the same. A suitable drive means may beapplied to any of the shafts or gears, and in the present case themanual handle 24, previously referred to, is applied to the shaft 46 ofintermediate gear 44. In preferred form the gear 44 has the samediameter as the gears 49 and 42, so that the handle turns through a halfrevolution, and as an additional refinement the handle is so mounted ororiented on shaft 46 that it points toward that branch port to which thecommon port has been connected.

The switch mechanism is preferably provided with over-the-center springsto put the mechanism in one end position or the other. In the presentcase there are two relatively powerful pull springs 50 and 52 (FIG. 15).These are stationarily anchored at 54 and 56, and are connected to thegears 40 and 42 at points 69 and 62, which are located diametricallyaway from the cranks 32 and 34. Thus in FIG. 15 the pull springs urgethe U bend 30 toward the ports 14 and 18. In FIG. 16 the pull springsare on dead center, and the mechanism is in a highly unstable condition.In FIG. 17 the pull springs urge the U bend 30" toward the ports 14 and16.

The parts referred to in FIGS. 15, 16 and 17 are also shown in FIGS. 3and 4, where they have the same reference numbers and will be readilyrecognizable.

To further assure good electrical contact between the movable U bend andthe mating seats formed at the inner ends of the ports, I provideresilient contact elements which may be described with initial referenceto FIG. 7 of the drawing. The U bend 30 comprises an inner conductor 64and outer conductor 66. The inner conductor is tubular or hollow inorder to conserve weight and metal, for we deal here with a sizablecoaxial line, specifically a 3%" line. The inner conductor 64 iscoaxially located within the outer conductor 66 by means of insulationspacer discs or so-called beads 68 and 70, and by two additional spacerrods at 72. The rods 72 and beads 68 are made of a suitable insulation,preferably Teflon (tetrafluoroethylene resin) The detailed constructionof spacer rod 72 is better shown in FIG. 8. The inner conductor 64 hasdiametrical holes receiving the stepped inner ends of the spacers, whilethe correspondingly stepped outer ends are received in threaded locatingplugs 74 received in bosses 76 and 78 formed integrally with the castouter conductor 66. The boss 76 is elliptical, rather than circular asin the case of boss 7-8, it extending upward to receive a grooved stud89, the purpose of which is described later.

Reverting to FIG. 7, the inner conductor 64 is closed at its ends bymetal plugs 82 which pass through the beads 68, and which threadedlyreceive metal seats 84. They also receive screws 86 which hold contactsprings 90. These are thin resilient metal discs made of berylliumcopper, preferably silver plated with a rhodium flash on top of thesilver. The periphery is radially slotted, as shown at 92 in FIG. 6, andis bent away from its seat 84 as shown in FIG. 7. Thus the resilientdisc serves as a contact spring for the inner conductor 64.

There is also a contact spring for the outer conductor 66, and this is aring 94 of thin resilient sheet metal, the inner periphery of which isradially slotted, as shown at 96 in FIG. 6, and which is bent away fromits seat 98 as shown in FIG. 7. The material and plating are the same asfor the disc 88. The outer periphery or base of the ring 94 is securedto the seat, and in the present case this is done in simple fashion bymerely tucking the outer periphery beneath the inner ends of a fewretainer pins. In this case there are four retainer pins, shown at 100in FIG. 6. One of these pins is shown to much larger scale in FIG. 9, inwhich it will be seen that a pin 100 driven through a hole 182 has itsinner end 104 overlying the outer or base portion of the ring 94, whilethe slotted inner portion 96 is bent away from the solid metal seat 98.With this method of retaining the contact ring it is readily removableand replaceable, it being simply warped or sprung out of or intoposition beneath the pins.

Ready changeability of the contact springs is desirable becausemishandling of the switch may cause arcing and consequent burning of thecontact springs. Power is supposed to be shut off before operating aswitch of this character, but an operator may forget and change theswitch without cutting off the power, in which case severe arcing mayresult, with possible damage to the contact springs.

Such casual mounting of the outer spring might be thought to providepoor, instead of good electrical contact, by reason'of failure tofixedly secure the base of the ring to resist cantilever movement of theinner or slotted periphery of the spring. However this is taken care ofin the present switch by giving the opposed seat not only rigid contactparts which bear against the slotted parts of the contact springs, butalso rigid base parts which bear against the unslotted base parts of thecontact springs, with the rigid contact parts and the rigid base partsbeing so relatively stepped that the slotted spring parts are deflected,while the unslotted spring parts are supported.

This will be clear from inspection of FIG. 10, in which the seat 98carries contact spring 94, the slotted portion of which normally assumesthe broken line position 96. The mating seat formed at the inner end ofa switch port is stepped to provide a rigid contact part 112 and a rigidbase part 114. These parts are so relatively stepped that the unslottedperiphery of contact spring 94 is tightly clamped between its seat 98and the base part 114 at the same time that the contact part 112. bearsagainst and defleets the slotted part from the broken line position 96to the solid line position 96. The tight clamping of the contact springbetween the parts 98 and 114 eliminates the need for a better or morerigid mounting of the spring contact ring.

The relation of the seat of a port to the exposed connector of the portwill be seen with reference to FIG. 5, in which the seat for the innerconductor is shown at 120, while the seat for the outer conductor isshown at 112, 114. On examination of the seat 126 it will be seen thatit is hollowed at the center to clear the mounting screw of the springcontact disc (90 in FIGS. 6 and 7), and that it too is stepped to clampand hold the unslotted base portion of the contact spring while bearingagainst the slotted pe ripheral portion of the contact spring. While notvisible in FIG. 5, the annular seat 114 is radially notched at fourpoints on its periphery to clear the inner ends of the four pins 108shown in FIGS. 6 and 9.

Other details shown in FIG. 5 are the assembly of hollow inner conductor122 with end plugs 124. These parts are held assembled with the seat andthe bullet 2% by means of a center screw 126 acting as a tie rod. Thisinner conductor assembly is centered within the flanged outer conductor128 by means of insulation beads 13%).

Reference has previously been made to the deeply grooved stud 80 shownin FIGS. 6 and 8. This is mounted near the outermost part of the U bend,and referring to FIG. 1, it cooperates with one or another of two spacedsupport plates 132 and 134. Referring to FIG. 2, plate 134 is secured toa boss 136 cast integrally with the wall 138 of the switch housing. Theplates 132 and 134 are so located that they receive the grooved stud 80in the manner shown in FIG. 11, it being understood that plate 134 isused when the U bend 30 is in the position shown in FIG. 1, and plate132 is used when the- U bend is in the opposite position. Thisconstruction holds the U bend against lateral movement at its outer orcurved portion, which portion is somewhat remote from the crankscarrying the inner portion of the bend.

Referring now to FIG. 12 of the drawing, the handle 24 is preferablyprovided with a locking means. Specifically there is a pilot pin 140moved by a thumb button 142 connected to a lever 144 pivoted at 146 andcon nected at 148 to pilot 140. The button is normally moved outward bya compression spring 151). The pilot 140 is received in either of twodiametrically related holes 152 or 154 in a detent plate 156. This plateis mounted directly on the cover plate 26 of the switch. The handle issecured to the shaft 46 of the intermediate gear, as by means of alocking pin or screw 158.

The particular handle here shown is one which is commercially available,it being made by Barkelew Electric Manufacturing Co. of Middletown,Ohio.

Referring to FIG. 13, the pilot plate 156 differs from the usualpractice in that the pilot holes 152 and 154 are not truly diametrical.They are offset slightly to one side, and specifically to that sidewhich increases the travel of the operating handle so that it issomewhat more than 180. The holes are tapered to facilitate entry of thepilot, and the effect is to insure tight seating of the U bend.

Referring to FIG. 3, the pull exerted by the springs 5i) and 52 createsfriction at the books at the ends of the springs. To minimize thisfriction I line the grooves receiving the books with nylon rings, shownat 160 in FIGS. 3 and 4. One of the rings 160 also is shown in FIG. 14.I have found that a very simple way to apply such nylon rings is toemploy rings which are large enough to slip over the posts 54, 56 orstuds 60, 62 receiving the same. In such case the ring is substantiallylarger in diameter than the groove intended to receive the same, but Ihave found that the hook of the spring simply deforms the ring toelliptical configuration, with the ex cess part of the ellipse idle, asshown in FIGS. 3 and 14, and that the resulting assembly functions justas well as with the nylon ring fitted to the bottom of the groove.

Reverting to FIG. 1, the mechanism is mounted on a subframe comprising arectangular mounting plate 164 which is secured to the cast housing bymeans of a row of four screws shown at 166. This plate 164 providesupper bearings for the gear shafts 36 and 38, as is best shown in FIGS.3 and 4, where the mounting plate 164 and associated mechanism has beenremoved from the switch housing. The lower ends of shafts 36 and 38 arereceived in bearings cast integrally with the bottom wall 138 of thehousing, such bearings being shown in broken lines at 168 in FIG. 4, andin solid lines in FIG. 2.

Reverting to FIG. 1, the subassembly further includes a top plate 170which is mounted above the mounting plate 164 by means of three spacersand bolts. In FIG. 14 it will be seen that spacer 54 and its associatedbolt 55 act also to anchor the stationary hook of spring 50. Revertingto FIG. 1, the top plate 170 is triangular at its forward end, which isheld by a single spacer and bolt 172. In FIG. 3 the top plate has beenremoved to better expose the mechanism, but the three spacers and boltsare indicated at 54, 56 and 57, it being understood that the nuts shownare actually located above, rather than below the top plate.

The top plate 170 acts as an additional bearing for the intermediategear shaft 46 which carries the operating handle.

Referring to FIG. 4, the cranks 32, 33, 34, and each has a hub portion180 which is secured to its operating shaft. It further has a crank pinportion 182. These parts may be made integral or may be brazed or weldedtogether. The inner ends of the crank pins 182 are received in bushingsor bearings 184 set into the cast U bend 30.

FIG. 4 also shows bearings 186 in mounting plate 164 for the gearshafts, and it shows the upper ends of spacers 54 and 56 with theirgrooves and nylon liners 160 for receiving the hooks of the pullsprings. For clarity the pull springs themselves have been omitted inFIG. 4. Although the spacers 54 and 56 are aligned with the shafts 36and 38, it will be understood that they are far apart, as shown in FIG.3, and that the gears and 42 are overhung secured at the very ends oftheir shafts. This is necessary because the pull springs move past theends of the shafts when the gears turn 180 degrees, as was explained inconnection with FIGS. 15, 16, and 17, and the dead center position inwhich the springs pass the ends of the shafts is shown in FIG. 16.

It may be mentioned that when the cover plate 26 is applied to thehousing, a rectangular gasket 190 (FIG. 12) is preferably interposed,and the parts are drawn together by a large number of closely spacedscrews (3&2 in FIG. 2), the holes for which are indicated at 194 inFIG. 1. Thus the unit may be made gas-tight, which is desirable when thesystem is to be pressurized. In such case appropriate gaskets are alsoemployed at the flanges 22, and an O ring is used on handle shaft 46 asshown .at 194 in FIGS. 2 and 12.

The present switch is dimensioned to be received directly in a 3% inchcoaxial line with standard E.I.A. flange connections. However, otherconnections may be used, for example, the Marmann quick disconnectflange.

The switch was designed to operate over a frequency range of from 755 to985 mc., and to handle up to 10 kw. average power. The VSWR was not toexceed 1.1 maximum; the insertion loss was not to exceed 0.15 db; andthe isolation between branches 16 and 18 was to be 70 db minimum. Inactual practice the switch greatly exceeds these requirements. Itoperates efficiently over the entire frequency range of the transmissionline.

The switch so far has been described as a single-pole double-throwswitch, but the same construction may be used for a double-poledouble-throw switch, or a triplepole double throw switch, and so on.This is done by placing the ports and the U bends side by side, andlengthening the shafts to provide linkage for simultaneously moving allof the U bends. This is schematically illustrated in FIG. 2a, in whichthere are two U bends 30 and 239, disposed side by side for simultaneousmovement. The shaft 236 corresponds to the shaft'36 previouslydescribed; the gear 240 corresponds to the gear 40; the cranks 232 and233 correspond to the cranks 32 and 33; and an extra double crank 232'is disposed between the two U bends. In FIG. 2a the cranks are shown indead center position, with the over-the-center spring 259 extended, sothat the linkage is in unstable position. This has been done to moreclearly show the cranks. It will be understood that there are two suchshafts and sets of cranks, with gears and springs, all as previouslydescribed, that is, a view such as FIG. 3 could remain unchanged. Itwill also be understood that by rigidly connecting the U bend 30 to theU bend 230 the intermediate crank 232' could be omitted.

It is believed that the construction, operation, and method of use of myimproved coaxial switch, as well as the advantages thereof, will beapparent from the foregoing detailed description. It will also beapparent that, while I have shown and described the switch in preferredform, changes may be made in the structure shown without departing fromthe scope of the invention as sought to be defined in the followingclaims.

I claim:

1. A switch for microwave energy comprising a common port, a branch porton one side of the common port, a branch port on the opposite side ofthe common port, said branch ports being equally spaced from said commonport, a U bend dimensioned to join the common port and either branchport, parallel shafts extending transversely of the aforesaid ports oneither side of the common port, a crank on each shaft adjacent the Ubend with the free ends of the cranks pivotally carrying the U bend toform a parallelogram linkage, and means to rotate said shafts in orderto bodily move the U bend on an arcuate path between positionsconnecting the common port with either branch port.

2. A coaxial switch comprising a common coaxial port, a branch coaxialport on one side of the com-mon port, a branch coaxial port on theopposite side of the common port, said branch ports being equally spacedfrom said common port, a U bend coaxial connector dimensioned to jointhe common port and either branch port, parallel shafts extendingtransversely of the coaxial conductors on either side of the commonport, two cranks on each shaft straddling the U bend with their freeends pivotally carrying the U bend to form a parallelogram linkage, andmeans to rotate said shafts in order to bodily move the U bend on anarcuate path between positions connecting the common port with eitherbranch port.

3. A coaxial switch comprising a com-mon coaxial port, a branch coaxialport on one side of the common port, a branch coaxial port on theopposite side of the common port, said branch ports being equally spacedfrom said common port, a U bend coaxial connector dimensioned to jointhe common port and either branch port; parallel shafts extendingtransversely of the coaxial conductors on either side of the com-monport, two cranks on each shaft straddling the U bend with their freeends pivo-tally carrying the U bend to form parallelogram linkage, andmeans to rotate said shafts in order to bodily move the U bend on anarcuate path between positions connecting the common port with eitherbranch port, said means including gears of equal diameter on saidshafts,

an intermediate gear for driving said shaft gears, and a means forturning one of the gears.

4. A coaxial switch comprising a common coaxial port, a branch coaxialport on one side of the common port, a branch coaxial port on theopposite side of the common port, said branch ports being equally spacedfrom said common port, a U bend coaxial connector dimensioned to jointhe common port and either branch port, parallel shafts extendingtransversely of the coaxial conductors on either side of the commonport, two cranks on each shaft straddling the U bend with their freeends pivotally carrying the U bend to form parallelogram linkage, andmeans to rotate said shafts in order to bodily move the U bend on anarcuate path between positions connecting the common port with eitherbranch port, said means including gears of equal diameter on saidshafts, an intermediate gear for driving said shaft gears, and a handlefor turning said intermediate gear.

5. A coaxial switch comprising a common coaxial port, a branch coaxialport on one side of the common port, a branch co-axial port on theopposite side of the common port, said branch ports being equally spacedfrom said common port, a U bend coaxial connector dimensioned to jointhe common port and either branch port, parallel shafts extendingtransversely of the coaxial conductors on either side of the commonport, two cranks on each shaft straddling the U bend with their freeends pivotally carrying the U bend to form parallelogram linkage, andmeans to rotate said shafts in order to bodily move the U bend on anarcuate path between positions connecting the common port with eitherbranch port, said means including gears of equal diameter on saidshafts, an intermediate gear for driving said shaft gears, and a handlefor turning one of the gears, said inter-mediate gear having the samediameter as the shaft gears, whereby a half-turn of the handle changesthe switch from one position to the other.

6. A coaxial switch comprising a common coaxial port, a branch coaxialport on one side of the common port, a branch coaxial port on theopposite side of the common port, said branch ports being equally spacedfrom said common port, a U bend coaxial connector dimensioned to jointthe common port and either branch port, parallel shafts extendingtransversely of the coaxial conductors on either side of the commonport, two cranks on each shaft straddling the U bend with their freeends pivotally carrying the U bend to form parallelogram linkage, andmeans to rotate said shafts in order to bodily move the U bend on anarcuate path between positions connecting the common port with eitherbranch port, said means including gears of equal diameter on saidshafts, an intermediate gear for driving said shaft gears, and a handlefor turning said intermediate gear, said-intermediate gear having thesame diameter as the shaft gears, whereby a half-turn of the handlechanges the switch from one position to the other, said handle being sooriented on said gear that it points to the branch port to which thecommon port has been connected.

7. A switch as defined in claim 1 in which the linkage is provided withrelatively powerful over-the-center pull springs which urge the U bendtoward the ports connected thereby.

8. A coaxial switch as defined in claim 2 in which relatively powerfulpull springs are so connected to said shafts at points locateddiametrically away from the cranks of the parallelogram linkage that thepull springs act as overthe-center springs to urge the U bend toward theports connected thereby.

9. A coaxial switch as defined in claim 4 in which the shaft gears areoverhung at the ends of their shafts and have crank pins, and in whichrelatively powerful pull springs are connected to said crank pins, saidcrank pins being located diametrically away from the cranks of theparallelogram linkage, whereby the pull springs act as over-the-centersprings to urge the U bend toward the ports connected thereby.

10. A coaxial switch as defined in claim 2 in which the ports lead toseats, and in which the ends of the U bend provide mating seats, and inwhich the seats are provided with contact springs to insure goodelectrical contact between the ports and the U bend, said contactsprings including a disc for the inner conductor, said disc being arelatively thin resilient metal disc the contact periphery of which isradially slotted and dished away from its seat and the center base ofwhich is secured to its seat.

11. A coaxial switch as defined in claim 2 in which the ports lead toseats, and in which the ends of the U bend provide mating seats, and inwhich the seats are provided with contact springs to insure goodelectrical contact between the ports and the U bend, said contactsprings including a disc for the inner conductor, said disc being arelatively thin resilient metal disc the contact periphery of which isradially slotted and dished away from its seat and the center base ofwhich is secured to its seat, the opposed seat having a rigid contactpart which bears against the slotted contact part of said contactspring, and having a rigid base part which bears against the base partof said contact spring, the said rigid contact part and rigid base partbeing so stepped that the slotted contact parts of said spring contactare deflected while the base part of said spring contact is fixedlysupported.

12. A switch as defined in claim 1 in which the ports lead to seats, andin which the ends of the U bend provide mating seats, and in which theseats are provided with contact springs to insure good electricalcontact between the ports and the U bend, said contact springs includinga ring for the outer conductor, said ring being a ring of thin resilientsheet metal the contact periphery of which is radially slotted and bentaway from its seat and the base periphery of which is secured to itsseat.

13. A switch as defined in claim 1 in which the ports lead to seats, andin which the ends of the U bend provide mating seats, and in which theseats are provided with contact springs to insure good electricalcontact between the ports and the U bend, said contact springs includinga ring for the outer conductor, said ring being a ring of thin resilientsheet metal the contact periphery of which is radially slotted and bentaway from its seat and the base periphery of which is secured to itsseat, the opposed seat having a rigid contact part which bears againstthe slotted contact part of said contact spring, and having a rigid basepart which bears against the base part of said contact spring, the saidrigid contact part and rigid base part being so stepped that the slottedcontact parts of said spring contact are deflected while the base partof said spring contact is fixedly supported.

14. A coaxial switch as defined in claim 2 in which the ports lead toseats, and in which the ends of the U bend provide mating seats, and inwhich the seats are provided with contact springs to insure goodelectrical contact between the ports and the U bend, said contactsprings including a disc for the inner conductor and a ring for theouter conductor, said disc being a relatively thin resilient metal discthe contact periphery of which is radially slotted and dished away fromits seat and the center base of which is secured to its seat, and saidring being a ring of thin resilient sheet metal the contact periphery ofwhich is radially slotted and bent away from its seat and the baseperiphery of which is secured to its seat.

15. A coaxial switch as defined in claim 2 in which the ports lead toseats, and in which the ends of the U bend provide mating seats, and inwhich the seats are provided with contact springs to insure goodelectrical contact between the ports and the U bend, said contactsprings including a disc for the inner conductor and a ring for theouter conductor, said disc being a relatively thin resilient metal discthe contact periphery of which is radially slotted and dished away fromits seat and the center base of which is secured to its seat, and saidring being a ring of thin resilient sheet metal the contact periphery ofwhich is radially slotted and bent away from its seat and the baseperiphery of which is secured to its seat, the opposed seat having rigidcontact parts which bear against the slotted contact parts of saidcontact springs, and having rigid base parts which bear against the baseparts of said contact springs, the said rigid contact parts and rigidbase parts being so stepped that the slotted contact parts of saidspring contacts are deflected while the base parts of said springcontacts are fixedly supported.

16. A switch as defined in claim 1, in which the switch has a stationaryframe, and in which the outer part of the U bend includes a deeplygrooved stud, and in which the frame of the switch has locating plateswhich receive the grooved stud to locate the outer part of the U bend.

17. A coaxial switch as defined in claim 2 in which the switch has astationary frame, and in which the outer part of the U bend includes adeeply grooved stud, and in which the frame of the switch has locatingplates which receive the grooved stud to locate the outer part of the Ubend.

18. A coaxial switch as defined in claim 4 in which the handle has apilot pin, a push button to release said pilot pin, and pilot holes toreceive the pilot pin, said pilot holes having tapered mouths.

19. A coaxial switch as defined in claim 5 in which the handle has apilot pin, a push button to release said pilot pin, and pilot holes toreceive the pilot pin, said pilot holes having tapered mouths and beinglocated slightly offset from a diametrical relation, such as to cause alittle more than 180 travel of the operating handle.

20. A switch as defined in claim 1 in which the linkage is provided withrelatively powerful over-the-center pull springs which urge the U bendtoward the ports connected thereby, and in which the ends of theover-thecenter pull springs have hooks received in grooves, and in whichthe grooves are lined by nylon rings to reduce friction.

21. A coaxial switch as defined in claim 2 in which relatively powerfulpull springs are so connected to said shafts at points locateddiametrically away from the cranks of the parallelogram linkage that thepull springs act as over-the-center springs to urge the U bend towardthe ports connected thereby, and in which the ends of theover-the-center pull springs have hooks received in grooves, and inwhich the grooves are lined by nylon rings to reduce friction.

22. A coaxial switch as defined in claim 2 in which relatively powerfulpull springs are so connected to said shafts at points locateddiametrically away from the cranks of the parallelogram linkage that thepull springs act as over-the-center springs to urge the U bend towardthe ports connected thereby, and in which the ends of theover-the-center pull springs have hooks received in grooves, and inwhich the grooves are lined by nylon rings to reduce friction, and inwhich the rings have a diameter large enough to be received over thepins to reach the grooves, and in which the hooks deform the rings fromcircular to elliptical configuration.

23. A switch as defined in claim 1 in which there are two collateralbranch ports on each side of two collateral common ports, and twocollateral U bends, and in which the parallelogram linkage bodily movesboth U bends simultaneously, thereby providing a double-pole doublethrowswitch.

24. A switch as defined in claim 2 in which there are two collateralbranch ports on each side of two collateral common ports, and twocollateral U bends, and in which the parallelogram linkage bodily movesboth U bends simultaneously, thereby providing a double-pole doublethrowswitch.

25. A switch for microwave energy comprising a common port, a branchport on one side of the common port,

a branch port on the opposite side of the common port, said branch portsbeing equally spaced from said common port, a U bend dimensioned to jointhe common port and either branch port, a parallelogram linkage movablycarrying said U bend for bodily movement on an arcuate path betweenpositions joining the common port with either branch port, said portsleading to seats, the ends of the U bend providing mating seats, andsaid seats being provided with contact springs to insure good electricalcontact between the ports and the U bend, said contact springs includinga ring for the outer conductor, said ring being a ring of thin resilientsheet metal the contact periphery of which is radially slotted and bentaway from its seat and the base periphery of which is secured to itsseat.

26. A switch for microwave energy comprising a common port, a branchport on one side of the common port, a branch port on the opposite sideof the common port, said branch ports being equally spaced from saidcommon port, a U bend dimensioned to join the common port and eitherbranch port, a parallelogram linkage movably carrying said U bend forbodily movement on an arcuate path between positions joining the commonport with either branch port, said ports leading to seats, the ends ofthe U bend providing mating seats, said seats being provided withcontact springs to insure good electrical contact between the ports andthe U bend, said contact springs including a ring for the outerconductor, said ring being a ring of thin resilient sheet metal thecontact pe ripheiy of which is radially slotted and bent away from itsseat and the base periphery of which is secured to its seat, the opposedseat having a rigid contact part which bears against the slotted contactpart of said contact spring, and having a rigid base part which bearsagainst the base part of said contact spring, the said rigid contactpart and rigid base part being so stepped that the slotted contact partsof said spring contact are deflected while the base part of said springcontact is fixedly supported.

27. A switch for microwave energy comprising a common port, a branchport on one side of the common port, a branch port on the opposite sideof the common port, said branch ports being equally spaced from saidcommon port, a U bend dimensioned to join the common port and eitherbranch port, a parallelogram linkage movably carrying said U bend forbodily movement on an arcuate path between positions joining the commonport with either branch port, a'stationary frame carrying the aforesaidports, the outer part of the U bend including a deeply grooved stud, andthe frame having locating plates which receive the grooved stud tolocate the outer part of the U bend.

28. A switch for microwave energy comprising a comprising a common port,a branch port on one side of the common port, a branch port on theopposite side of the common port, said branch ports being equally spacedfrom said common port, a U bend dimensioned to join the common port andeither branch port, a parallelogram linkage movably carrying said U bendfor bodily movement on an arcuate path between positions joining thecommon port with either branch port, said linkage being provided withrelatively powerful over-the-center pull springs which urge the U bendtoward the ports connected thereby, and the ends of the over-the-centerpull springs having hooks received in grooves, and the said groovesbeing lined by nylon rings to reduce friction.

References Cited in the file of this patent UNITED STATES PATENTS1,893,046 Austin Ian. 3, 1933 2,709,725 Bieber et al. May 31, 19552,825,775 Constantine et al. Mar. 4, 1958

